1. Field of the Invention
The present invention relates to a winding apparatus for winding a continuous web such as a microfilm.
2. Description of the Prior Art
In recent years, the microfilms are increasingly utilized for the purpose of reduction recording of ever increasing publications and documents and are utilized in combination with known microfilm handling systems such as microfilm reader, microfilm reader-printer or microfilm retriever for the retrieval of the desired information and for the projection on a screen or the printing of thus retrieved information. The microfilms are available in the form of a continuous rolled film, a microfiche or in other forms, and the microfilm in the continuous form is generally wound as a roll on a reel or in a cartridge. In a microfilm apparatus such rolled microfilm is advanced from a feed section through a retrieval section or a projection section to a winding section for take-up on a winding shaft or reversed from said winding section to the feed section, and the retrieval or projection of a desired image frame is achieved during the advancement or reverse advancement of the microfilm. In such microfilm apparatus there is generally employed an automatic loading system for feeding the microfilm from the feed section to the winding section, wherein the microfilm is automatically drawn, in response to the actuation of an operating button, for example from a film cartridge fitted into said microfilm apparatus and advanced through a determined path for automatic take-up on a winding shaft in the winding section. Such apparatus is however generally associated with a drawback in that, in case the leading end of the microfilm is not securely wound on the winding shaft but is jammed in the film path, the microfilm is folded and superposed on itself, eventually leading to the damage or breakage of film. For this reason there is generally provided a microswitch along the film path for detecting the superposed state of the film caused by such jamming and interrupting the film advancement, but such method is insufficient for preventing the damage on the film because of the relatively slow detection of or the frequent failure in the film jamming.
The object of the present invention is to provide a web winding apparatus capable of preventing the abovementioned drawback and rapidly and securely detecting any abnormality in the web transportation resulting from the jamming, breakage etc. of the web thereby avoiding the damage on the web.
The present invention is applicable to various web-shaped materials such as microfilm, magnetic tape or 8-mm movie film.